net/bridge/br_netlink.c

   1 /*
   2  *      Bridge netlink control interface
   3  *
   4  *      Authors:
   5  *      Stephen Hemminger               <shemminger@osdl.org>
   6  *
   7  *      This program is free software; you can redistribute it and/or
   8  *      modify it under the terms of the GNU General Public License
   9  *      as published by the Free Software Foundation; either version
  10  *      2 of the License, or (at your option) any later version.
  11  */
  12
  13 #include <linux/kernel.h>
  14 #include <linux/slab.h>
  15 #include <linux/etherdevice.h>
  16 #include <net/rtnetlink.h>
  17 #include <net/net_namespace.h>
  18 #include <net/sock.h>
  19 #include <uapi/linux/if_bridge.h>
  20
  21 #include "br_private.h"
  22 #include "br_private_stp.h"
  23
  24 static inline size_t br_port_info_size(void)
  25 {
  26         return nla_total_size(1)        /* IFLA_BRPORT_STATE  */
  27                 + nla_total_size(2)     /* IFLA_BRPORT_PRIORITY */
  28                 + nla_total_size(4)     /* IFLA_BRPORT_COST */
  29                 + nla_total_size(1)     /* IFLA_BRPORT_MODE */
  30                 + nla_total_size(1)     /* IFLA_BRPORT_GUARD */
  31                 + nla_total_size(1)     /* IFLA_BRPORT_PROTECT */
  32                 + nla_total_size(1)     /* IFLA_BRPORT_FAST_LEAVE */
  33                 + 0;
  34 }
  35
  36 static inline size_t br_nlmsg_size(void)
  37 {
  38         return NLMSG_ALIGN(sizeof(struct ifinfomsg))
  39                 + nla_total_size(IFNAMSIZ) /* IFLA_IFNAME */
  40                 + nla_total_size(MAX_ADDR_LEN) /* IFLA_ADDRESS */
  41                 + nla_total_size(4) /* IFLA_MASTER */
  42                 + nla_total_size(4) /* IFLA_MTU */
  43                 + nla_total_size(4) /* IFLA_LINK */
  44                 + nla_total_size(1) /* IFLA_OPERSTATE */
  45                 + nla_total_size(br_port_info_size()); /* IFLA_PROTINFO */
  46 }
  47
  48 static int br_port_fill_attrs(struct sk_buff *skb,
  49                               const struct net_bridge_port *p)
  50 {
  51         u8 mode = !!(p->flags & BR_HAIRPIN_MODE);
  52
  53         if (nla_put_u8(skb, IFLA_BRPORT_STATE, p->state) ||
  54             nla_put_u16(skb, IFLA_BRPORT_PRIORITY, p->priority) ||
  55             nla_put_u32(skb, IFLA_BRPORT_COST, p->path_cost) ||
  56             nla_put_u8(skb, IFLA_BRPORT_MODE, mode) ||
  57             nla_put_u8(skb, IFLA_BRPORT_GUARD, !!(p->flags & BR_BPDU_GUARD)) ||
  58             nla_put_u8(skb, IFLA_BRPORT_PROTECT, !!(p->flags & BR_ROOT_BLOCK)) ||
  59             nla_put_u8(skb, IFLA_BRPORT_FAST_LEAVE, !!(p->flags & BR_MULTICAST_FAST_LEAVE)))
  60                 return -EMSGSIZE;
  61
  62         return 0;
  63 }
  64
  65 /*
  66  * Create one netlink message for one interface
  67  * Contains port and master info as well as carrier and bridge state.
  68  */
  69 static int br_fill_ifinfo(struct sk_buff *skb,
  70                           const struct net_bridge_port *port,
  71                           u32 pid, u32 seq, int event, unsigned int flags,
  72                           u32 filter_mask, const struct net_device *dev)
  73 {
  74         const struct net_bridge *br;
  75         struct ifinfomsg *hdr;
  76         struct nlmsghdr *nlh;
  77         u8 operstate = netif_running(dev) ? dev->operstate : IF_OPER_DOWN;
  78
  79         if (port)
  80                 br = port->br;
  81         else
  82                 br = netdev_priv(dev);
  83
  84         br_debug(br, "br_fill_info event %d port %s master %s\n",
  85                      event, dev->name, br->dev->name);
  86
  87         nlh = nlmsg_put(skb, pid, seq, event, sizeof(*hdr), flags);
  88         if (nlh == NULL)
  89                 return -EMSGSIZE;
  90
  91         hdr = nlmsg_data(nlh);
  92         hdr->ifi_family = AF_BRIDGE;
  93         hdr->__ifi_pad = 0;
  94         hdr->ifi_type = dev->type;
  95         hdr->ifi_index = dev->ifindex;
  96         hdr->ifi_flags = dev_get_flags(dev);
  97         hdr->ifi_change = 0;
  98
  99         if (nla_put_string(skb, IFLA_IFNAME, dev->name) ||
 100             nla_put_u32(skb, IFLA_MASTER, br->dev->ifindex) ||
 101             nla_put_u32(skb, IFLA_MTU, dev->mtu) ||
 102             nla_put_u8(skb, IFLA_OPERSTATE, operstate) ||
 103             (dev->addr_len &&
 104              nla_put(skb, IFLA_ADDRESS, dev->addr_len, dev->dev_addr)) ||
 105             (dev->ifindex != dev->iflink &&
 106              nla_put_u32(skb, IFLA_LINK, dev->iflink)))
 107                 goto nla_put_failure;
 108
 109         if (event == RTM_NEWLINK && port) {
 110                 struct nlattr *nest
 111                         = nla_nest_start(skb, IFLA_PROTINFO | NLA_F_NESTED);
 112
 113                 if (nest == NULL || br_port_fill_attrs(skb, port) < 0)
 114                         goto nla_put_failure;
 115                 nla_nest_end(skb, nest);
 116         }
 117
 118         /* Check if  the VID information is requested */
 119         if (filter_mask & RTEXT_FILTER_BRVLAN) {
 120                 struct nlattr *af;
 121                 const struct net_port_vlans *pv;
 122                 struct bridge_vlan_info vinfo;
 123                 u16 vid;
 124                 u16 pvid;
 125
 126                 if (port)
 127                         pv = nbp_get_vlan_info(port);
 128                 else
 129                         pv = br_get_vlan_info(br);
 130
 131                 if (!pv || bitmap_empty(pv->vlan_bitmap, BR_VLAN_BITMAP_LEN))
 132                         goto done;
 133
 134                 af = nla_nest_start(skb, IFLA_AF_SPEC);
 135                 if (!af)
 136                         goto nla_put_failure;
 137
 138                 pvid = br_get_pvid(pv);
 139                 for (vid = find_first_bit(pv->vlan_bitmap, BR_VLAN_BITMAP_LEN);
 140                      vid < BR_VLAN_BITMAP_LEN;
 141                      vid = find_next_bit(pv->vlan_bitmap,
 142                                          BR_VLAN_BITMAP_LEN, vid+1)) {
 143                         vinfo.vid = vid;
 144                         vinfo.flags = 0;
 145                         if (vid == pvid)
 146                                 vinfo.flags |= BRIDGE_VLAN_INFO_PVID;
 147
 148                         if (test_bit(vid, pv->untagged_bitmap))
 149                                 vinfo.flags |= BRIDGE_VLAN_INFO_UNTAGGED;
 150
 151                         if (nla_put(skb, IFLA_BRIDGE_VLAN_INFO,
 152                                     sizeof(vinfo), &vinfo))
 153                                 goto nla_put_failure;
 154                 }
 155
 156                 nla_nest_end(skb, af);
 157         }
 158
 159 done:
 160         return nlmsg_end(skb, nlh);
 161
 162 nla_put_failure:
 163         nlmsg_cancel(skb, nlh);
 164         return -EMSGSIZE;
 165 }
 166
 167 /*
 168  * Notify listeners of a change in port information
 169  */
 170 void br_ifinfo_notify(int event, struct net_bridge_port *port)
 171 {
 172         struct net *net;
 173         struct sk_buff *skb;
 174         int err = -ENOBUFS;
 175
 176         if (!port)
 177                 return;
 178
 179         net = dev_net(port->dev);
 180         br_debug(port->br, "port %u(%s) event %d\n",
 181                  (unsigned int)port->port_no, port->dev->name, event);
 182
 183         skb = nlmsg_new(br_nlmsg_size(), GFP_ATOMIC);
 184         if (skb == NULL)
 185                 goto errout;
 186
 187         err = br_fill_ifinfo(skb, port, 0, 0, event, 0, 0, port->dev);
 188         if (err < 0) {
 189                 /* -EMSGSIZE implies BUG in br_nlmsg_size() */
 190                 WARN_ON(err == -EMSGSIZE);
 191                 kfree_skb(skb);
 192                 goto errout;
 193         }
 194         rtnl_notify(skb, net, 0, RTNLGRP_LINK, NULL, GFP_ATOMIC);
 195         return;
 196 errout:
 197         if (err < 0)
 198                 rtnl_set_sk_err(net, RTNLGRP_LINK, err);
 199 }
 200
 201
 202 /*
 203  * Dump information about all ports, in response to GETLINK
 204  */
 205 int br_getlink(struct sk_buff *skb, u32 pid, u32 seq,
 206                struct net_device *dev, u32 filter_mask)
 207 {
 208         int err = 0;
 209         struct net_bridge_port *port = br_port_get_rcu(dev);
 210
 211         /* not a bridge port and  */
 212         if (!port && !(filter_mask & RTEXT_FILTER_BRVLAN))
 213                 goto out;
 214
 215         err = br_fill_ifinfo(skb, port, pid, seq, RTM_NEWLINK, NLM_F_MULTI,
 216                              filter_mask, dev);
 217 out:
 218         return err;
 219 }
 220
 221 static const struct nla_policy ifla_br_policy[IFLA_MAX+1] = {
 222         [IFLA_BRIDGE_FLAGS]     = { .type = NLA_U16 },
 223         [IFLA_BRIDGE_MODE]      = { .type = NLA_U16 },
 224         [IFLA_BRIDGE_VLAN_INFO] = { .type = NLA_BINARY,
 225                                     .len = sizeof(struct bridge_vlan_info), },
 226 };
 227
 228 static int br_afspec(struct net_bridge *br,
 229                      struct net_bridge_port *p,
 230                      struct nlattr *af_spec,
 231                      int cmd)
 232 {
 233         struct nlattr *tb[IFLA_BRIDGE_MAX+1];
 234         int err = 0;
 235
 236         err = nla_parse_nested(tb, IFLA_BRIDGE_MAX, af_spec, ifla_br_policy);
 237         if (err)
 238                 return err;
 239
 240         if (tb[IFLA_BRIDGE_VLAN_INFO]) {
 241                 struct bridge_vlan_info *vinfo;
 242
 243                 vinfo = nla_data(tb[IFLA_BRIDGE_VLAN_INFO]);
 244
 245                 if (vinfo->vid >= VLAN_N_VID)
 246                         return -EINVAL;
 247
 248                 switch (cmd) {
 249                 case RTM_SETLINK:
 250                         if (p) {
 251                                 err = nbp_vlan_add(p, vinfo->vid, vinfo->flags);
 252                                 if (err)
 253                                         break;
 254
 255                                 if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
 256                                         err = br_vlan_add(p->br, vinfo->vid,
 257                                                           vinfo->flags);
 258                         } else
 259                                 err = br_vlan_add(br, vinfo->vid, vinfo->flags);
 260
 261                         if (err)
 262                                 break;
 263
 264                         break;
 265
 266                 case RTM_DELLINK:
 267                         if (p) {
 268                                 nbp_vlan_delete(p, vinfo->vid);
 269                                 if (vinfo->flags & BRIDGE_VLAN_INFO_MASTER)
 270                                         br_vlan_delete(p->br, vinfo->vid);
 271                         } else
 272                                 br_vlan_delete(br, vinfo->vid);
 273                         break;
 274                 }
 275         }
 276
 277         return err;
 278 }
 279
 280 static const struct nla_policy ifla_brport_policy[IFLA_BRPORT_MAX + 1] = {
 281         [IFLA_BRPORT_STATE]     = { .type = NLA_U8 },
 282         [IFLA_BRPORT_COST]      = { .type = NLA_U32 },
 283         [IFLA_BRPORT_PRIORITY]  = { .type = NLA_U16 },
 284         [IFLA_BRPORT_MODE]      = { .type = NLA_U8 },
 285         [IFLA_BRPORT_GUARD]     = { .type = NLA_U8 },
 286         [IFLA_BRPORT_PROTECT]   = { .type = NLA_U8 },
 287 };
 288
 289 /* Change the state of the port and notify spanning tree */
 290 static int br_set_port_state(struct net_bridge_port *p, u8 state)
 291 {
 292         if (state > BR_STATE_BLOCKING)
 293                 return -EINVAL;
 294
 295         /* if kernel STP is running, don't allow changes */
 296         if (p->br->stp_enabled == BR_KERNEL_STP)
 297                 return -EBUSY;
 298
 299         /* if device is not up, change is not allowed
 300          * if link is not present, only allowable state is disabled
 301          */
 302         if (!netif_running(p->dev) ||
 303             (!netif_oper_up(p->dev) && state != BR_STATE_DISABLED))
 304                 return -ENETDOWN;
 305
 306         p->state = state;
 307         br_log_state(p);
 308         br_port_state_selection(p->br);
 309         return 0;
 310 }
 311
 312 /* Set/clear or port flags based on attribute */
 313 static void br_set_port_flag(struct net_bridge_port *p, struct nlattr *tb[],
 314                            int attrtype, unsigned long mask)
 315 {
 316         if (tb[attrtype]) {
 317                 u8 flag = nla_get_u8(tb[attrtype]);
 318                 if (flag)
 319                         p->flags |= mask;
 320                 else
 321                         p->flags &= ~mask;
 322         }
 323 }
 324
 325 /* Process bridge protocol info on port */
 326 static int br_setport(struct net_bridge_port *p, struct nlattr *tb[])
 327 {
 328         int err;
 329
 330         br_set_port_flag(p, tb, IFLA_BRPORT_MODE, BR_HAIRPIN_MODE);
 331         br_set_port_flag(p, tb, IFLA_BRPORT_GUARD, BR_BPDU_GUARD);
 332         br_set_port_flag(p, tb, IFLA_BRPORT_FAST_LEAVE, BR_MULTICAST_FAST_LEAVE);
 333
 334         if (tb[IFLA_BRPORT_COST]) {
 335                 err = br_stp_set_path_cost(p, nla_get_u32(tb[IFLA_BRPORT_COST]));
 336                 if (err)
 337                         return err;
 338         }
 339
 340         if (tb[IFLA_BRPORT_PRIORITY]) {
 341                 err = br_stp_set_port_priority(p, nla_get_u16(tb[IFLA_BRPORT_PRIORITY]));
 342                 if (err)
 343                         return err;
 344         }
 345
 346         if (tb[IFLA_BRPORT_STATE]) {
 347                 err = br_set_port_state(p, nla_get_u8(tb[IFLA_BRPORT_STATE]));
 348                 if (err)
 349                         return err;
 350         }
 351         return 0;
 352 }
 353
 354 /* Change state and parameters on port. */
 355 int br_setlink(struct net_device *dev, struct nlmsghdr *nlh)
 356 {
 357         struct ifinfomsg *ifm;
 358         struct nlattr *protinfo;
 359         struct nlattr *afspec;
 360         struct net_bridge_port *p;
 361         struct nlattr *tb[IFLA_BRPORT_MAX + 1];
 362         int err;
 363
 364         ifm = nlmsg_data(nlh);
 365
 366         protinfo = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_PROTINFO);
 367         afspec = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_AF_SPEC);
 368         if (!protinfo && !afspec)
 369                 return 0;
 370
 371         p = br_port_get_rtnl(dev);
 372         /* We want to accept dev as bridge itself if the AF_SPEC
 373          * is set to see if someone is setting vlan info on the brigde
 374          */
 375         if (!p && ((dev->priv_flags & IFF_EBRIDGE) && !afspec))
 376                 return -EINVAL;
 377
 378         if (p && protinfo) {
 379                 if (protinfo->nla_type & NLA_F_NESTED) {
 380                         err = nla_parse_nested(tb, IFLA_BRPORT_MAX,
 381                                                protinfo, ifla_brport_policy);
 382                         if (err)
 383                                 return err;
 384
 385                         spin_lock_bh(&p->br->lock);
 386                         err = br_setport(p, tb);
 387                         spin_unlock_bh(&p->br->lock);
 388                 } else {
 389                         /* Binary compatability with old RSTP */
 390                         if (nla_len(protinfo) < sizeof(u8))
 391                                 return -EINVAL;
 392
 393                         spin_lock_bh(&p->br->lock);
 394                         err = br_set_port_state(p, nla_get_u8(protinfo));
 395                         spin_unlock_bh(&p->br->lock);
 396                 }
 397                 if (err)
 398                         goto out;
 399         }
 400
 401         if (afspec) {
 402                 err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
 403                                 afspec, RTM_SETLINK);
 404         }
 405
 406         if (err == 0)
 407                 br_ifinfo_notify(RTM_NEWLINK, p);
 408
 409 out:
 410         return err;
 411 }
 412
 413 /* Delete port information */
 414 int br_dellink(struct net_device *dev, struct nlmsghdr *nlh)
 415 {
 416         struct ifinfomsg *ifm;
 417         struct nlattr *afspec;
 418         struct net_bridge_port *p;
 419         int err;
 420
 421         ifm = nlmsg_data(nlh);
 422
 423         afspec = nlmsg_find_attr(nlh, sizeof(*ifm), IFLA_AF_SPEC);
 424         if (!afspec)
 425                 return 0;
 426
 427         p = br_port_get_rtnl(dev);
 428         /* We want to accept dev as bridge itself as well */
 429         if (!p && !(dev->priv_flags & IFF_EBRIDGE))
 430                 return -EINVAL;
 431
 432         err = br_afspec((struct net_bridge *)netdev_priv(dev), p,
 433                         afspec, RTM_DELLINK);
 434
 435         return err;
 436 }
 437 static int br_validate(struct nlattr *tb[], struct nlattr *data[])
 438 {
 439         if (tb[IFLA_ADDRESS]) {
 440                 if (nla_len(tb[IFLA_ADDRESS]) != ETH_ALEN)
 441                         return -EINVAL;
 442                 if (!is_valid_ether_addr(nla_data(tb[IFLA_ADDRESS])))
 443                         return -EADDRNOTAVAIL;
 444         }
 445
 446         return 0;
 447 }
 448
 449 static size_t br_get_link_af_size(const struct net_device *dev)
 450 {
 451         struct net_port_vlans *pv;
 452
 453         if (br_port_exists(dev))
 454                 pv = nbp_get_vlan_info(br_port_get_rcu(dev));
 455         else if (dev->priv_flags & IFF_EBRIDGE)
 456                 pv = br_get_vlan_info((struct net_bridge *)netdev_priv(dev));
 457         else
 458                 return 0;
 459
 460         if (!pv)
 461                 return 0;
 462
 463         /* Each VLAN is returned in bridge_vlan_info along with flags */
 464         return pv->num_vlans * nla_total_size(sizeof(struct bridge_vlan_info));
 465 }
 466
 467 static struct rtnl_af_ops br_af_ops = {
 468         .family                 = AF_BRIDGE,
 469         .get_link_af_size       = br_get_link_af_size,
 470 };
 471
 472 struct rtnl_link_ops br_link_ops __read_mostly = {
 473         .kind           = "bridge",
 474         .priv_size      = sizeof(struct net_bridge),
 475         .setup          = br_dev_setup,
 476         .validate       = br_validate,
 477         .dellink        = br_dev_delete,
 478 };
 479
 480 int __init br_netlink_init(void)
 481 {
 482         int err;
 483
 484         br_mdb_init();
 485         err = rtnl_af_register(&br_af_ops);
 486         if (err)
 487                 goto out;
 488
 489         err = rtnl_link_register(&br_link_ops);
 490         if (err)
 491                 goto out_af;
 492
 493         return 0;
 494
 495 out_af:
 496         rtnl_af_unregister(&br_af_ops);
 497 out:
 498         br_mdb_uninit();
 499         return err;
 500 }
 501
 502 void __exit br_netlink_fini(void)
 503 {
 504         br_mdb_uninit();
 505         rtnl_af_unregister(&br_af_ops);
 506         rtnl_link_unregister(&br_link_ops);
 507 }